When Five Becomes Nine
by Kat Silver
Summary: There are five senses that let humans experience the outside world, but there are others that let humans experience themselves  as well as the people who have become so much a part of oneself as to be inseparable .
1. The Senses that Experience the World

**Sense of Sight**

John Watson was interesting to watch.

He looked very unassuming. Sherlock figured that this was a conscious decision on John's part. But Sherlock knew the truth. John had deft hands, whether he was fixing tea or examining a body. They were a doctor's hands, quick and precise in their movements.

Sherlock loved to watch John pull on the invisible armour of the soldier persona that he could never quite leave behind. It wasn't that John wasn't a confident man in his everyday life, far from that, but when he drew himself up, back straight, shoulders square, head high, he became someone more. Give him a gun and he became mesmerizing, hands steady, feet planted, something fatal and beautiful all at once.

Sherlock wasn't normally given to such sentimental hyperbole, but he knows artistry when he sees it.

**Sense of Hearing**

John Watson's voice was uniquely expressive.

Sherlock and John had infrequent but quite spectacular shouting matches. Sherlock had seen John angry at him, and was quite familiar with that tone of voice, the one that meant that Sherlock had done something "wrong" and didn't care and John didn't approve.

John's angry voice and John's command voice were very similar, but the steel behind the commanding tone brooked no argument from anyone. John had even managed to use the voice effectively on Irene Adler. Unbeknownst to them at the time, Sherlock had overheard every word.

But Sherlock was also familiar with John's joking, happy voice as they bantered about cases or about crap telly shows. It was warm, if a voice could be categorized as such, and John's laugh was infectious, making even Sherlock smile.

**Sense of Smell**

John Watson smells of tea and wool and London and something uniquely his own.

Sometimes he smelled like cologne or toast or the chip shop or, once after a particularly difficult case that almost ended quite badly, river water and the coppery tang of blood. Not his own blood, fortunately, but the blood of the man he'd disarmed and then subdued so the police could take the man away.

Sherlock had wrinkled his nose at the smell of river that clung to John, but John was too high on adrenaline to notice, although John had taken a shower as soon as he'd gotten home. Then he'd smelled like soap and shampoo and clean.

**Sense of Touch**

John Watson was surprisingly muscular.

Under the coat and the jumper and the shirt, John was still in good shape from the army. The few times Sherlock had touched John, he had felt that through the layers of cloth and wool.

Sherlock, though, could still remember feeling the trembling in John's body as he'd stripped off the Semtex vest that Moriarty had strapped on him. Sherlock almost recoiled at touching the vest itself, trying to keep the coat between his hands and it, and then slung them both as far away as he could at the first opportunity.

**Sense of Taste**

Sherlock honestly had no idea what John Watson tasted like.

Tea, probably, if Sherlock had to make a deduction. Wool, cotton. Sweat, if he'd been running. Soap, maybe, after a shower. Toast. Chinese food.

They both came in laughing and exhilarated after catching a particularly stupid thief. John was gasping out something that the thief had said to which Sherlock had made a retort that had left the thief gaping at him in open mouthed confusion.

"I swear, I could kiss you sometimes," John gasped out, still laughing, and then froze. Sherlock froze as well, and then hung up his coat and turned to John. "Sherlock, I'm so—"

Sherlock cut him off mid-word by pressing his mouth to John's. John froze again for a moment.

And then John was kissing him back.

A distant part of Sherlock's brain registered that John did indeed taste faintly of tea, but John mostly tasted like _John_. Another distant, smaller part, was registering how interesting tasting another person was, how it was both touching and tasting at the same time, engaging two senses at once.

Sherlock could smell John's scent that was _woolcottonLondonJohn_, see that John had his eyes closed, hear John make a small pleased noise in his throat, feel the softness of John's hair under Sherlock's left hand and the weave of his jumper under his right.

But mostly Sherlock was kissing John, because that was something new and different and unique and, somehow, impossibly perfect.


	2. The Senses that Experience the Self

**Sense of Pain**

John Watson really was an excellent doctor.

John wasn't Sherlock-level observant by any means, but one day they were sitting in a cafe drinking coffee and John started discreetly pointing at people and diagnosing them. Carpal tunnel, back pain, hip replacement, scoliosis. It's not that Sherlock _forgets_ that John's a doctor as well as a soldier. It's just that sometimes he doesn't remember until John reminded him.

John frequently patched up Sherlock's various scrapes and bruises that he collects on cases. He's gentle but firm, good with a needle when Sherlock needs stitches. He made Sherlock eat and sleep, which Sherlock rebelled against, but it's really more for the sake of rebelling than of any real desire to thwart John's ministrations.

**Sense of Temperature**

John Watson made the flat seem warmer, just by being in a room.

Sherlock knew that the temperature change from one person being in a room would be negligible to the point of immeasurability, so he knows that John doesn't _literally_ make a room warmer by being in it. It just seems that way.

And then it was Sherlock's turn to fall in the river. When John helped to pull him from the water, Sherlock's lips were going blue and he was shaking with cold. John pulled off Sherlock's sodden jacket (he'd shed the coat before he'd gone in the water) and wrapped one blanket around his shoulders and another around his legs. He curled up as much as he could, trying to warm himself as John dried his hair with yet another blanket. But the shaking wouldn't stop, so John pulled off his own coat and unwrapped the top blanket and wrapped his arms around Sherlock before tugging the blanket around both of them. John breathed against Sherlock's neck, the warm air sending goose bumps down Sherlock's spine. The resulting shiver wasn't due completely to the cold.

**Sense of Balance**

John Watson liked to keep things on an even keel.

Sherlock appreciated the stabilizing influence John has on him, even if he didn't always show it. Didn't ever show it, truth be told.

John was tea when he's agitated and coffee in the mornings and blankets when he's cold and food at least once a day, usually more. John was sleep and caretaking and responsibility. He's crap telly on rainy days and good Chinese after a case. He's medicine and bandages and steady hands and the comforting sensation of having another person looking out for you.

And, best of all, he was a conscience.

**Proprioception**

Sherlock saw John Watson in Moriarty's hands, and it was as though he'd lost one of his own limbs.

If Moriarty was to kill John, he wouldn't just be burning Sherlock's heart. He'd be amputating a hand, an arm, a balancing force, the warmth of companionship, Sherlock's shield against the world.

Sherlock always knew where John was afterwards. Periodically, when he realised John wasn't in the same room, he would stop and listen, only resuming his pacing or experiment when he heard the creak of floorboards or a cough or a snore. Once, just days after Moriarty and the pool, Sherlock had woken to find John gone from the flat and John's phone on the coffee table. He'd paced for half an hour until John returned carrying the shopping. John stopped in the doorway, startled to see Sherlock, and Sherlock breathed a sigh of relief. John's mouth twitched in a humourless smile and he'd apologised for leaving his phone.

Mycroft sneered at caring, at sentiment. Sherlock knew that it wasn't an advantage, it was a weakness, but once the caring started it was so hard to stop.

Proprioception is the knowledge of where your limbs are in relation to you without having to see them.

The titles of these two parts I borrowed from something Hank Green said in a video on YouTube. The video can be found here, the part I'm talking about starts at around the two minute mark: .com/watch?v=Yj0eXvMpnak

There are other senses that the human body has (sense of hunger, etc.) but I chose these because they're kind of internal senses that can be influenced by external stimuli.

Also, it's my birthday, so this is kind of a reverse gift from me to you. I hope you enjoy.


End file.
